Devices, systems and methods for an oscillating crown drive for rotational atherectomy

Abstract

The present invention is directed in various methods, devices and systems relating to rotational atherectomy. More specifically, an oscillating driver is connected to a drive shaft, or torque transfer tube, with abrasive element mounted thereon. The result provides a rotational working diameter for the rotating abrasive element that is larger than its resting diameter. Generally, the preferred abrasive element is concentric in profile and/or with center of mass collinear with the drive shaft's rotational axis. However, eccentric abrasive elements, both in terms of offsetting center of mass and/or geometric eccentricity may also be employed.

What is claimed is: 
     
       1. A rotational atherectomy system adapted for high-speed rotation and having an abrasive head adapted to move from a resting diameter when there is no system rotation to a working diameter greater than the resting diameter during high-speed rotation of the system, comprising:
 an elongated flexible non-oscillating drive shaft having a lumen therethrough, a rotational axis and a distal end; and 
 an oscillating section attached proximate the distal end of the elongated non-oscillating drive shaft and comprising:
 a radially offsetting drive shaft attachment attached to the non-oscillating drive shaft and having a centered lumen therethrough, the centered lumen in fluid communication with the lumen of the non-oscillating drive shaft and further being coincident with the rotational axis of the non-oscillating drive shaft, and an attachment point radially offset from the centered lumen, and 
 a flexible oscillating drive shaft directly attached to the attachment point of the radially offsetting drive shaft attachment and extending distally and longitudinally therefrom; and 
 the abrading head attached to the flexible oscillating drive shaft and spaced distally from the attachment point. 
 
 
     
     
       2. The rotational atherectomy system of  claim 1 , wherein the radially offsetting drive shaft attachment is circular. 
     
     
       3. The rotational atherectomy system of  claim 1 , further comprising the oscillating drive shaft having a rotational axis. 
     
     
       4. The rotational atherectomy system of  claim 3 , further comprising the abrading head being concentric and comprising a center of mass that is coincident with the rotational axis of the oscillating drive shaft. 
     
     
       5. The rotational atherectomy system of  claim 3 , further comprising the abrading head being concentric and having a center of mass that is radially offset from the rotational axis of the oscillating drive shaft. 
     
     
       6. The rotational atherectomy system of  claim 3 , further comprising the abrading head being eccentric and comprising a center of mass that is radially offset from the rotational axis of the oscillating drive shaft. 
     
     
       7. The rotational atherectomy system of  claim 6 , wherein the abrading head is geometrically eccentric. 
     
     
       8. The rotational atherectomy system of  claim 6 , further comprising the radially offset attachment point and the eccentric abrading head's center of mass that is radially offset from the rotational axis of the oscillating drive shaft aligned longitudinally within a longitudinal plane through the radially offsetting drive shaft attachment. 
     
     
       9. The rotational atherectomy system of  claim 8 , further comprising a zero degree radial offset between the longitudinally aligned radially offset attachment point and the radially offset center of mass. 
     
     
       10. The rotational atherectomy system of  claim 8 , further comprising a 180-degree radial offset between the longitudinally aligned radially offset attachment point and the radially offset center of mass.